.app {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.app__nav {

}

.app__nav-link {
  display: inline-block;
  margin: 5px;
}

.app__content {
  display: flex;
  flex-basis: auto;
  flex-grow: 1;
  overflow: hidden;
}

fieldset {
  border: 1px solid lightgray;
}
